Atrioventricular and left bundle-branch block (I44) ICD-10-CM
The I44 code range covers atrioventricular and left bundle-branch block with 13 ICD-10-CM diagnosis codes. 10 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Codes in the I44 Range 13 codes · 10 billable
- I44 Atrioventricular and left bundle-branch blockNon-billable
- I44.0 Atrioventricular block, first degree
- I44.1 Atrioventricular block, second degree
- I44.2 Atrioventricular block, complete
- I44.3 Other and unspecified atrioventricular blockNon-billable
- I44.30 Unspecified atrioventricular block
- I44.39 Other atrioventricular block
- I44.4 Left anterior fascicular block
- I44.5 Left posterior fascicular block
- I44.6 Other and unspecified fascicular blockNon-billable
- I44.60 Unspecified fascicular block
- I44.69 Other fascicular block
- I44.7 Left bundle-branch block, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the I44 range.
Atrioventricular Block
Impaired impulse conduction from HEART ATRIA to HEART VENTRICLES. AV block can mean delayed or completely blocked impulse conduction.
Left Anterior Fascicular Block by ECG Finding
An electrocardiographic finding of a slightly widened QRS duration (typically less than 120 ms) with leftward frontal plane QRS axis and typically small Q waves in leads I and aVL. (CDISC)
Left Posterior Fascicular Block by ECG Finding
An electrocardiographic finding of an S1Q3 pattern and QRS axis greater than or equal to 120 degrees. It is usually seen in association with other abnormalities (e.g. RBBB or RVH). (CDISC)
About the I44 Code Range
These heart blocks include atrioventricular block, fascicular block, and left bundle-branch block.
Atrioventricular block is separated into first degree, second degree, complete, and other or unspecified forms. The other or unspecified branch splits further into I44.30 for unspecified and I44.39 for other atrioventricular block. Fascicular block separates left anterior from left posterior and other or unspecified forms. The latter splits into unspecified and other fascicular block. I44.7 identifies left bundle-branch block, unspecified.
Questions About This Page
How many billable codes are in the I44 range?
Of the 13 codes in this range, 10 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the I44 range classify?
The range classifies atrioventricular and left bundle-branch block. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
